This invention pertains to the polymerization of haloalkynes and in particular to the formation of highly conjugated, polyunsaturated polymeric materials.
There is a continuing search for highly conjugated, polyunsaturated synthetic organic polymers for use in the area of electrically conducting polymers and in the coatings industry. Polyacetylene is a material which has attracted a great deal of attention because it can be doped to produce electrically conducting polymers. Materials of this kind have found applications in the electronics industry as electrodes or components of batteries and also as light-weight wiring. However, one of the drawbacks of polyacetylene is that it is insoluble in water and organic solvents and thus cannot be readily fabricated into shaped articles and forms. This property of polyacetylene renders it equally undesirable as a coating material.
It is, therefore, an object of this invention to provide a means of producing highly conjugated polymers which are soluble and have the potential to become electrically conducting by treating these materials with dopants.
It is another object to provide highly conjugated, polyunsaturated organic polymers which can be easily crosslinked to serve as durable coating materials.
It is known in the prior art that nickel triaryl phosphine complexes can polymerize acetylenes, but there are a number of limitations imposed by previous methods. In a number of cases using catalyst systems comprising reduced nickel triaryl phosphine complexes, only low molecular weight polymers were obtained. Thus, in U.S. Pat. No. 2,961,330 the products are described as liquid materials with one to about 6 repeating units. Another limitation disclosed in the latter patent is the fact that disubstituted acetylenes do not react. When costly reducing agents were avoided and simple complexes of nickel halides were used (as in British No. 1,021,948), then relatively large ratios of catalyst to alkyne had to be used.
U.S. Pat. Nos. 4,263,466 and 4,326,989 disclose a process and a catalyst composition for the coupling of aryl monochlorides. It would be unexpected, therefore, that the catalyst composition disclosed in these patents would allow halo alkynes to be polymerized without any of the above-mentioned limitations.